Before the Class 10 mathematics exam held on March 28, Central Board of Secondary Education chairperson Anita Karwal had received an e-mail a day informing her about the paper being leaked.

The e-mail sender stated that the mathematics paper was leaked on WhatsApp and that the exam should be cancelled. The mail also contained 12 images of the handwritten mathematics paper allegedly leaked on WhatsApp.

In an effort to identify the sender of the e-mail, the police had written to Google, asking it to share the details of the e-mail ID. The police had also sent a reminder to the website on Friday to expedite the process.

Two directors of a private coaching centre in Jharkhand were arrested and four students detained on Saturday in connection with the CBSE question paper leak case, police said.

With Saturday’s arrest, 12 people, including Class-X and XII students, have been apprehended in the CBSE leak case from Jharkhand’s Chatra district, the police said.

The police had on Friday detained six Class 10 students in the case.

The police crackdown in the case started after two cases were registered in the CBSE Class-X mathematics and Class-XII economics papers leak incident earlier this week.

Among those apprehended today, four are students of different schools in the district and two directors of a private coaching centre here, police said.

A Class 11 student from the Navodaya Vidyalaya campus in the region was detained, police said. He had hid chits containing answers of a leaked question paper in the school’s bathroom, police said. Of the 12 arrested, two students are from Patna, they said.

The directors of the private coaching centre have been put under arrest, the police added.